Silena NIM 761F: Connection scheme

This document contains the channel connection scheme of the remotely controllable Silena NIM 761 main amplifier.

Channel

Signal

0

silicon detector 1

1

silicon detector 2

2

silicon detector 3

3

silicon detector 4

4

silicon detector 5

5

6

7

8

BaF2 detector 1

9

BaF2 detector 2

10

BaF2 detector 3

11

BaF2 detector 4

12

13

14

15

Silena NIM 761F: RS-485 Interface Connection

Dr. Stephen Mallion

Introduction

This document aims to explain the interfacing of a personal computer (PC) to a Silena NIM 761F (or chain of such devices), and to correct the errors which appear in Version 1.02 of the User’s Manual.

Connection Scheme

The serial port of the host computer is to be connected via an adapter cable to an interface adapter (RS232 <-> RS485), which in turn is to be connected by means of a multidrop cable to the NIM 761F (which can, if required, be the first in a chain of such units). Communication between the PC and the NIM 761F is effected in half duplex mode, and thus the T+ and T- pins of the interface adapter are tied respectively to its R+ and R- pins. The multidrop cable connects T+ to the upper pin of the upper 2 pin connector on the rear panel of the NIM 761F, and T- to the lower pin of the upper 2 pin connector. Internal connections within the module ensure that the upper and lower pins of the upper connector are tied respectively to the upper and lower pins of the lower connector.

The configuration described above ensures that neither the PC nor the NIM 761F can transmit and receive data simultaneously, as a result of which the interface adapter should be used in the T-RTS, R-/RTS mode. The interface adapter is designed so that when operating in this mode, either the transmitter or the receiver is enabled depending on whether the RTS (Request To Send) signal from the controlling device (PC) is active or in-active. Note, however, that the Silena control program A16COMM makes use of DTR (Data Terminal Ready) flow control, and so in the present case it is the DTR signal from the PC which controls the enabling of the transmitter and the receiver.

In order to specify the adapter cable, it is necessary to know whether the PC is data terminal equipment (DTE) or data communication equipment (DCE). Although it is not clear whether all PCs are necessarily DTE, a conventional PC and a lap-top PC which were used in recent tests were both found to operate in DTE mode. Thus in the following discussion it shall be assumed that the PC constitutes DTE. The interface adapter can be operated successfully in either DCE or DTE mode (selectable by a switch) provided that the adapter cable is compatible with the selected mode. The required connections are shown in the following tables, in which IA stands for Interface Adapter, Rx for Receive, Tx for Transmit, Gnd for Ground and CTS for Clear To Send.

Function

PC (DTE)

9 pin connector

IA (DTE)

25 pin connector

Function

Rx <-

2

2

<- Tx

Tx ->

3

3

-> Rx

DTR ->

4

5

-> CTS

Gnd

5

7

Gnd

Function

PC (DTE)

9 pin connector

IA (DCE)

25 pin connector

Function

Rx <-

2

3

<- Tx

Tx ->

3

2

<- Rx

DTR ->

4

4

<- CTS

Gnd

5

7

Gnd

Function

PC (DTE)

25 pin connector

IA (DTE)

25 pin connector

Function

Tx ->

2

3

-> Rx

Rx <-

3

2

<- Tx

Gnd

7

7

Gnd

DTR ->

20

5

-> CTS

Function

PC (DTE)

25 pin connector

IA (DCE)

25 pin connector

Function

Tx ->

2

2

-> Rx

Rx <-

3

3

<- Tx

Gnd

7

7

Gnd

DTR ->

20

4

-> CTS

Note that Version 1.02 of the User’s Manual attempts to provide the information given in the first and the third of the above tables, but does so incorrectly.

Hardware

Currently, the adapter referred to above is located inside the electronics cabinet no. 3 (left) in room 40/108. It consists of the appropriate DB25-DB9 connector and the RS485-RS232 interface. The two-wire cable has to be connected with Tx+ up and Tx- down.